WebOS runner refactor

[SankarRealm]

Summary

Refactor the WebOS port to use the upstream SDL2 backend and the refactored Runner architecture instead of maintaining a separate monolithic WebOS SDL2/platform implementation.

Changes

• Use the upstream src/backends/sdl2.c backend for WebOS.
• Simplify src/webos/main.c to the platform entry point.
• Add the WebOS-specific platformLog() implementation in src/webos/log.c.
• Remove the obsolete src/webos/platform.c implementation.
• Remove the unused src/webos/stat_compat.c.
• Use the common STB implementation instead of a WebOS-specific STB_DS implementation.
• Force legacy GL off for WebOS and use the modern GLES2/EGL renderer.
• Integrate WebOS into the common CMake platform/backend configuration.

Testing

Built successfully from a clean CMake configuration using the WebOS SDK SDL2 2.30.12.

Tested on an actual LG webOS TV:

• Launches successfully
• Renders correctly
• Runs normally
• Controller input works
• D-pad diagonals work

Notes

The WebOS B-button/exit-window behavior is not addressed by this PR. It will be investigated separately.

This PR is focused on moving the WebOS port onto the upstream/refactored Runner architecture and removing the duplicated WebOS-specific SDL2/platform implementation.

[leap0x7b]

Are you new to GitHub? You probably should push those changes to #450 instead of making another PR since that one isn't even merged yet

[SankarRealm]

Are you new to GitHub? You probably should push those changes to #450 instead of making another PR since that one isn't even merged yet

yes Im new to GitHub😅 thanks for helping, shall I close this PR and push to #450 then?